Washington's 20th legislative district

Mossyrock is a city in Lewis County, Washington, United States. The population was 768 at the 2020 census.

Harmony is an unincorporated town in Lewis County, Washington. The community is located near the junction of the Cowlitz River and Mayfield Lake, and is situated off Route 122, north of Mossyrock.

The Tilton River is a tributary of the Cowlitz River, in the U.S. state of Washington. Named for territorial surveyor James Tilton, it flows for about 29 miles (47 km), entirely within Lewis County.

Ike Kinswa State Park is a public recreation area on the northern side of Lake Mayfield, located three miles (4.8 km) northwest of Mossyrock in Lewis County, Washington. The state park covers 421 acres (170 ha) that include 46,000 feet (14,000 m) of shoreline mostly along the Tilton River including the point where the Tilton and Cowlitz rivers once merged. The park offers boating, fishing, swimming, waterskiing and windsurfing plus facilities for camping, hiking, and mountain biking, It is managed by the Washington State Parks and Recreation Commission.

Riffe Lake is a long reservoir on the Cowlitz River in the U.S. state of Washington. The 23.5 mi (38 km) lake was created by the construction of Mossyrock Dam, the tallest dam in the state, in 1968 by Tacoma City Light (now Tacoma Power).

Mossyrock Dam is a concrete arch-gravity dam on the Cowlitz River near Mossyrock in Lewis County, Washington, United States. The reservoir created by the dam is called Riffe Lake. The primary purpose of the dam is hydroelectric production while flood control is a secondary function. The dam is the tallest in Washington state and its hydroelectric power station supplies 40% of Tacoma Power's electricity.

Silver Creek is an unincorporated community in Lewis County, Washington, United States. Silver Creek is located along U.S. Route 12 near its junction with Washington State Route 122, 5 miles (8.0 km) west of Mossyrock. Lake Mayfield is accessible 3.5 miles to the east. A post office called Silver Creek has been in operation since 1875. The community takes its name from nearby Silver Creek.

Cinebar is an unincorporated community in Lewis County, Washington, United States. It is located between State Route 508 and U.S. Route 12. Named for the cinnabar present in the mountains to the northeast, Cinebar is a rural area with a post office and fire station on State Route 508. Other communities near Cinebar include Silver Creek, Salkum, Morton, Onalaska, Napavine, Chehalis, and Centralia.

Swofford, also known as Swofford Valley, is an unincorporated community in central Lewis County, in the U.S. state of Washington. The town sits on the south shore of Riffe Lake, approximately 4.0 miles (6.4 km) southeast of Mossyrock.

KWJD-LP (92.1 FM) is a radio station broadcasting a religious format. Licensed to Onalaska, Washington, United States, the station is owned by Valley Life Broadcasting, Inc.The station changed its call sign from KTYG-LP to KWJD-LP on June 27, 2016.

Nesika was an unincorporated town in Lewis County, Washington, southeast of Mossyrock. It is now a flooded town.

Onalaska is an unincorporated community and census-designated place (CDP) in Lewis County, Washington, United States. As of the 2020 census it had a population of 657. Onalaska is located along Washington State Route 508.